Occluded blood vessels can be caused by a blood clot (i.e. thrombus) that forms in the blood vessel or by a blood clot that travels downstream (i.e. embolus). The blockage disrupts blood flow, which prevents oxygen and nutrients from being delivered to their intended locations. Tissue distal of a blood clot that is deprived of oxygen and nutrients can no longer function properly. For every minute that treatment is delayed, additional cellular death of critical tissue can occur.
Current technology for blood flow restoration, for example for treating cerebral arteries occluded by thrombi, can often take hours to reestablish flow in the artery, and can lead to unintended complications. Apparatuses and methods for treating cerebral thrombi are often ineffective or only partially effective at resolving thrombus removal, and may result in distal embolization or embolization of uninvolved arteries. For example, some current devices are designed to pierce through a thrombus, or are designed to deploy completely distal of the thrombus before engaging the thrombus. These devices can often fail to capture all of a thrombus, can damage vessel walls distal of a thrombus, can be difficult to maneuver, can unintentionally dislodge portions of a thrombus prior to capture, and/or can take significant amounts of time to restore blood flow.
Additional treatment options include endovascular therapy and/or pharmacological agents. Pharmacological agents, specifically thrombolytics, can be used to dissolve a thrombus and restore blood flow. However, these drugs often do not work in recanalizing the vessel, may not be suitable for some patients, and may take an extended length of time to work, which can impact the cellular death distal of the thrombus. Often these drugs are used within a short treatment window and those patients late in presentation will not be eligible for drug treatment. Also, these drugs can increase the risk to patients for incidences of hemorrhage.
Current technology for implantable members, for example stents for treating vasoconstriction or for closing off vessel wall ballooning in aneurysms or fistulae (e.g. aneurysm bridging devices), is also known. Balloon dilatable stents, for example, are commonly used to treat vasoconstriction or aneurysms. These balloon dilatable stents are often crimped over a non-expanded balloon in a non-dilated state, moved to the treatment location by means of a catheter system and then, by expanding the balloon, dilated and thus anchored within the vessel. Other devices include, for example, stents made of shape-memory material that possess a braid-like structure and are initially introduced and moved in a collapsed state through a catheter to the destination site where they expand either due to temperature changes or because the mechanical force exerted by the catheter is no longer effective.